What is stress?

Stress is, loosely defined, the result of a physiological or psychological stressor which results in the body undergoing adaptations to attempt to cope with the stressor. Using this concept we can see that training is fundamentally a stressor which ends the body to make the adaptation athletes seek to better prepare for future circumstances. When we think of stress we should distinguish between acute or temporary stressors and chronic stressors which last over a long time. Traditionally it was felt that while temporary stressors are easy to adapt to, chronic stress can lead to deleterious consequences for the body such as decreased immune function. Unfortunately, this simplistic concept has been challenged recently with new research showing that the stress response and subsequent outcome is sensitive to both the frequency of stressful episodes (with frequent but intermittent stressors being particularly bad for the body), while the outcome on physiological functions can have varying effects dependent on not just the stressor but the time duration of stress. Generally speaking though we can say the following:

1. Stressors lead to an adaptive response which in the short term makes the body better able to deal with the stressor.

2. Intermittent stressful episodes can lead to a ratcheting up of the stress response over time which can lead to people becoming more likely to suffer from stress related diseases.

3. Chronic stress will lead to the body shutting down non-essential systems related to growth and can lead to a situation where cortisol is chronically elevated.

Stress can accelerate the negative effects of diseases including but not limited to, hypertension, diabetes, atherosclerosis, ulcers, depression, mood disorders, insomnia and a whole host of autoimmune diseases. How then does it impact on athletes and bodybuilders?

Stress and Testosterone

When you experience a stressful situation, all of the body's resources are poured into surviving the immediate threat. Unfortunately, one of the outcomes of this is that the body decides there is no need to waste resources on optimistic activities like growth and reproduction so that muscle synthesis and testosterone levels drop in men (estrogen in women). Research shows that psychological stress such as this is reliably associated with drops in testosterone and elevation in cortisol which is a major stress hormone (1,2,3). Even watching films can have an impact on testosterone with one study showing pornographic films increased testosterone production while a stressful film showing dental surgery lowered testosterone (4). Even anticipating a stressor is enough to induce a stress response and cause an increase in cortisol in athletes preparing for competition (5) although there was no impact on testosterone. Note that we previously showed in our article on sleep how alleviated cortisol levels from a lack of sleep led to increases in bodyfat.

Training and testosterone

We all know that testosterone levels go up after heavy compound movements but drop after 45 minutes in the gym at which point you go catabolic right? We also know that athletes who train will have higher testosterone levels than non-athletes, right?

This popular belief is something that has been recycled so many times it has come to be accepted as fact but it seems to run counter to the evidence showing a generalised body response to any stressful event and for sure squats should be stressful. Research on sportsmen from various disciplines including rowers (6), cyclists (7), and endurance athletes (8) showed a decline in testosterone during differing time periods while a study on elite weight lifters in Finland (9) showed even these power athletes saw a drop in testosterone and increase in cortisol with more intensive training linked to worse endocrine outcomes. In spite of this, a subsequent reduction in training volume in this study led to cortisol levels to normalise and an improvement in the testosterone to cortisol ratio which preceded some personal best performances. Interestingly, over a longer period of time of one year there was no longer a statistical significant impact on testosterone or cortisol at all showing that over time the body is capable to adapting to the type of stress induced by weight training. Another study comparing effects on growth hormone and testosterone in young and old subjects (10) showed that while growth hormone rose significantly in the young subjects, both groups experienced a drop in testosterone from their training protocol.

Practical Guidelines

In light of the negative effects of stress on hormonal profile it is important to ensure we take steps to manage stress levels. From a training standpoint we need to be aware of times when we increase training volume and intensity and ensure we take steps to manage our recovery, possibly via supplemental strategies such as increasing intake of essential or branched chain amino acids or the use of adaptogens to normalise stress. At a minimum, we should ensure we sleep for at least eight hours every night given our past article noting negative effects on body composition. Additionally, when training volume, training frequency, and intensity goes up you should ensure you do so slowly. Making drastic increases in your training can lead to the body's adaptive response being overwhelmed which will accentuate the negative effect on testosterone and cortisol.

Other than ensuring we take steps to ensure we rest and recuperate adequately, the other main way we can limit the negative effects of stress is by adapting our training so that if we are going through a very stressful period in our lives (away from training), we reduce our training volume in the gym. This is very much dependent on the type of stress faced. In the face of moderate stress training can help us manage stress better but regardless of this fact it does not mean it would be a smart move to try to increase our training workload.

One final point to note is that in the presence of stress, when our hormones are primed to make us add fat and lose muscle it is important to keep protein intake high (1.5g per pound of bodyweight would be ideal) and not to overeat.

Summary

While there is little doubt that stress can cause a marked drop in testosterone, the effects of stress on training can be adapted to providing we limit training workload and our use of aerobic training. Where we encounter non-training related stress it would be wise to keep training stress at a minimum and employ the use of supplements designed to lower cortisol or boost testosterone to help offset the negative effects of stress on these hormones.

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